Amazon.com: BRAINWAVZ 4” Small Floating Shelf, Adhesive & Screw in, for Bluetooth Speakers, Cameras, Plants, Toys, Books & More, Easy to Install Shelves Wall Mount (White) : Electronics
Wall mount bracket for center channel and surround, found what worked : r/hometheater
Boston Acoustics BRAVO-IIW 4" / 1" 2 Way WALL / CORNER MOUNT Surround Sound Speaker (WHITE)
V-CORNER | Vecta | Monitor Audio
Speco Technologies 4" Corner Mount Modular Speaker SMSM4I1W6 B&H